From 414c0708d0d60eccf8345c405ac81cf32c43e901 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:06 +1100 Subject: CRED: Wrap task credential accesses in the SYSV IPC subsystem Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells Reviewed-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- ipc/mqueue.c | 6 +++--- ipc/shm.c | 5 +++-- ipc/util.c | 18 +++++++++++++----- 3 files changed, 19 insertions(+), 10 deletions(-) (limited to 'ipc') diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 68eb857cfde..abda5991d7e 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -117,8 +117,8 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode, inode = new_inode(sb); if (inode) { inode->i_mode = mode; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; + inode->i_uid = current_fsuid(); + inode->i_gid = current_fsgid(); inode->i_blocks = 0; inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME; @@ -507,7 +507,7 @@ static void __do_notify(struct mqueue_inode_info *info) sig_i.si_code = SI_MESGQ; sig_i.si_value = info->notify.sigev_value; sig_i.si_pid = task_tgid_vnr(current); - sig_i.si_uid = current->uid; + sig_i.si_uid = current_uid(); kill_pid_info(info->notify.sigev_signo, &sig_i, info->notify_owner); diff --git a/ipc/shm.c b/ipc/shm.c index 867e5d6a55c..0c3debbe32d 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -752,9 +752,10 @@ asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) goto out_unlock; if (!capable(CAP_IPC_LOCK)) { + uid_t euid = current_euid(); err = -EPERM; - if (current->euid != shp->shm_perm.uid && - current->euid != shp->shm_perm.cuid) + if (euid != shp->shm_perm.uid && + euid != shp->shm_perm.cuid) goto out_unlock; if (cmd == SHM_LOCK && !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) diff --git a/ipc/util.c b/ipc/util.c index 49b3ea615dc..c8a76701b6c 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -258,6 +258,8 @@ int ipc_get_maxid(struct ipc_ids *ids) int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) { + uid_t euid; + gid_t egid; int id, err; if (size > IPCMNI) @@ -272,8 +274,9 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) ids->in_use++; - new->cuid = new->uid = current->euid; - new->gid = new->cgid = current->egid; + current_euid_egid(&euid, &egid); + new->cuid = new->uid = euid; + new->gid = new->cgid = egid; new->seq = ids->seq++; if(ids->seq > ids->seq_max) @@ -616,13 +619,15 @@ void ipc_rcu_putref(void *ptr) int ipcperms (struct kern_ipc_perm *ipcp, short flag) { /* flag will most probably be 0 or S_...UGO from */ + uid_t euid = current_euid(); int requested_mode, granted_mode, err; if (unlikely((err = audit_ipc_obj(ipcp)))) return err; requested_mode = (flag >> 6) | (flag >> 3) | flag; granted_mode = ipcp->mode; - if (current->euid == ipcp->cuid || current->euid == ipcp->uid) + if (euid == ipcp->cuid || + euid == ipcp->uid) granted_mode >>= 6; else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid)) granted_mode >>= 3; @@ -784,6 +789,7 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd, struct ipc64_perm *perm, int extra_perm) { struct kern_ipc_perm *ipcp; + uid_t euid; int err; down_write(&ids->rw_mutex); @@ -803,8 +809,10 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd, if (err) goto out_unlock; } - if (current->euid == ipcp->cuid || - current->euid == ipcp->uid || capable(CAP_SYS_ADMIN)) + + euid = current_euid(); + if (euid == ipcp->cuid || + euid == ipcp->uid || capable(CAP_SYS_ADMIN)) return ipcp; err = -EPERM; -- cgit v1.2.3 From b6dff3ec5e116e3af6f537d4caedcad6b9e5082a Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:16 +1100 Subject: CRED: Separate task security context from task_struct Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- ipc/mqueue.c | 2 +- ipc/shm.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'ipc') diff --git a/ipc/mqueue.c b/ipc/mqueue.c index abda5991d7e..e1885b494ba 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -126,7 +126,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode, if (S_ISREG(mode)) { struct mqueue_inode_info *info; struct task_struct *p = current; - struct user_struct *u = p->user; + struct user_struct *u = p->cred->user; unsigned long mq_bytes, mq_msg_tblsz; inode->i_fop = &mqueue_file_operations; diff --git a/ipc/shm.c b/ipc/shm.c index 0c3debbe32d..264a9d33c5d 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -366,7 +366,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (shmflg & SHM_HUGETLB) { /* hugetlb_file_setup takes care of mlock user accounting */ file = hugetlb_file_setup(name, size); - shp->mlock_user = current->user; + shp->mlock_user = current->cred->user; } else { int acctflag = VM_ACCOUNT; /* @@ -767,7 +767,7 @@ asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) goto out_unlock; if(cmd==SHM_LOCK) { - struct user_struct * user = current->user; + struct user_struct *user = current->cred->user; if (!is_file_hugepages(shp->shm_file)) { err = shmem_lock(shp->shm_file, 1, user); if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ -- cgit v1.2.3 From 86a264abe542cfececb4df129bc45a0338d8cdb9 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:18 +1100 Subject: CRED: Wrap current->cred and a few other accessors Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- ipc/mqueue.c | 2 +- ipc/shm.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'ipc') diff --git a/ipc/mqueue.c b/ipc/mqueue.c index e1885b494ba..1151881ccb9 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -112,6 +112,7 @@ static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) static struct inode *mqueue_get_inode(struct super_block *sb, int mode, struct mq_attr *attr) { + struct user_struct *u = current_user(); struct inode *inode; inode = new_inode(sb); @@ -126,7 +127,6 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode, if (S_ISREG(mode)) { struct mqueue_inode_info *info; struct task_struct *p = current; - struct user_struct *u = p->cred->user; unsigned long mq_bytes, mq_msg_tblsz; inode->i_fop = &mqueue_file_operations; diff --git a/ipc/shm.c b/ipc/shm.c index 264a9d33c5d..38a055758a9 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -366,7 +366,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (shmflg & SHM_HUGETLB) { /* hugetlb_file_setup takes care of mlock user accounting */ file = hugetlb_file_setup(name, size); - shp->mlock_user = current->cred->user; + shp->mlock_user = current_user(); } else { int acctflag = VM_ACCOUNT; /* @@ -767,7 +767,7 @@ asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) goto out_unlock; if(cmd==SHM_LOCK) { - struct user_struct *user = current->cred->user; + struct user_struct *user = current_user(); if (!is_file_hugepages(shp->shm_file)) { err = shmem_lock(shp->shm_file, 1, user); if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ -- cgit v1.2.3 From 745ca2475a6ac596e3d8d37c2759c0fbe2586227 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:22 +1100 Subject: CRED: Pass credentials through dentry_open() Pass credentials through dentry_open() so that the COW creds patch can have SELinux's flush_unauthorized_files() pass the appropriate creds back to itself when it opens its null chardev. The security_dentry_open() call also now takes a creds pointer, as does the dentry_open hook in struct security_operations. Signed-off-by: David Howells Acked-by: James Morris Signed-off-by: James Morris --- ipc/mqueue.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'ipc') diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 1151881ccb9..d9393f8e4c3 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -594,6 +594,7 @@ static int mq_attr_ok(struct mq_attr *attr) static struct file *do_create(struct dentry *dir, struct dentry *dentry, int oflag, mode_t mode, struct mq_attr __user *u_attr) { + const struct cred *cred = current_cred(); struct mq_attr attr; struct file *result; int ret; @@ -618,7 +619,7 @@ static struct file *do_create(struct dentry *dir, struct dentry *dentry, if (ret) goto out_drop_write; - result = dentry_open(dentry, mqueue_mnt, oflag); + result = dentry_open(dentry, mqueue_mnt, oflag, cred); /* * dentry_open() took a persistent mnt_want_write(), * so we can now drop this one. @@ -637,8 +638,10 @@ out: /* Opens existing queue */ static struct file *do_open(struct dentry *dentry, int oflag) { -static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, - MAY_READ | MAY_WRITE }; + const struct cred *cred = current_cred(); + + static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, + MAY_READ | MAY_WRITE }; if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { dput(dentry); @@ -652,7 +655,7 @@ static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, return ERR_PTR(-EACCES); } - return dentry_open(dentry, mqueue_mnt, oflag); + return dentry_open(dentry, mqueue_mnt, oflag, cred); } asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode, -- cgit v1.2.3